Cathode active material for non-aqueous electrolyte rechargeable battery and manufacturing method for same, and non-aqueous electrolyte rechargeable battery

Abstract

To provide a cathode active material for a non-aqueous electrode rechargeable battery, with which it is possible to improve input/output characteristics, particularly by reducing resistance in a low SOC state in which DCIR increases, and to provide a manufacturing method for same. The cathode active material includes layered hexagonal crystal lithium nickel manganese composite oxide particles represented by the general formula (A): Li 1+u Ni x Mn y Co z M t O 2 (where 0≦u≦0.20, x+y+z+t=1, 0.30≦x ≦0.70, 0.10≦y≦0.55, 0≦z≦0.40, 0≦t≦0.10, and M is one or more elements selected from Al, Ti, V, Cr, Zr, Nb, Mo, and W), and further including Na, Mg, Ca and SO 4 , in which the total amount of Na, Mg and Ca is 0.01 to 0.1 mass %, the amount of SO 4 is 0.1 to 1.0 mass %, and the ratio of the integrated intensity of the diffraction peak on plane (003) to that on plane (104) obtained by powder X-ray diffraction measurement using CuKα rays is 1.20 or greater.

What is claimed is: 
     
       1. Cathode active material for a non-aqueous electrolyte rechargeable battery comprising:
 layered hexagonal crystal lithium nickel manganese composite oxide particles that are expressed by the general formula (A): Li 1+u Ni x Mn y Co z M t O 2  (where 0≦u≦0.20, x+y+z+t=1, 0.30≦x≦0.70, 0.10≦y≦0.55, 0≦z≦0.40, 0≦t≦0.10, and M is selected from one or more elements selected from among Al, Ti, V, Cr, Zr, Nb, Mo, and W); and further includes Na, Mg, Ca and SO 4 ; and wherein 
 the total amount of Na, Mg and Ca included is 0.01% by mass to 0.1% by mass, and the amount of SO 4  included is 0.1% by mass to 1.0% by mass; 
 sodium ions, magnesium ions and calcium ions are dissolved in Li sites; and 
 the ratio of the integrated intensity of the diffraction peak on plane (003) with respect to the integrated intensity of the diffraction peak on plane (104) that were obtained by power X-ray diffraction measurement that uses CuKα rays is 1.20 or greater wherein 
 a crystallization process for obtaining nickel manganese composite hydroxide particles that include secondary particles that are formed from an aggregation of plural primary particles, and are expressed by the general formula (B):: Ni x Mn y Co z M t (OH) 2+α (where x+y+z+t=1, 0.30≦x≦0.70, 0.10≦y≦0.55, 0≦z≦0.40, 0≦t≦0.10, 0≦α≦0.5, and M is at least one element that is selected from among Al, Ti, V, Cr, Zr, Nb, Mo, and W), and further includes Na, Mg, Ca and SO 4 , with the total amount of Na, Mg and Ca included being 0.01% by mass to 0.1% by mass, and the amount of SO 4  included being 0.1% by mass to 1.0% by mass; 
 a mixing process for obtaining a lithium mixture by mixing a lithium compound into the nickel manganese composite hydroxide particles that were obtained in the crystallization process so that the ratio of the number of atoms of Li with respect to the number of atoms of Ni, Mn, Co and M is 1:0.95 to 1.20; and 
 a calcination process for obtaining lithium nickel manganese composite oxide particles by performing calcination of the lithium mixture in an oxidizing atmosphere and at a calcination temperature of 850° C. to 1000° C., with T ave1  being the average temperature during the temperature rise from 650° C. to the calcination temperature, t 1  being the amount of time for the temperature to rise from 650° C. to the calcination temperature, T ave2  being the average temperature while the temperature is maintained at the calcination temperature, and t 2  being the amount of time that the temperature is maintained at the calcination temperature, and wherein a crystal growth index (G 1 ) that is defined by an Equation (a)
   Crystal growth index:  G   1 = T   ave1 × t   1   1/2   (a)
 
 
 
       is controlled so as to be 550° C.·h 1/2  to 1000° C.·h 1/2 , and a crystal growth index (G 2 ) that is defined by an Equation (b)
   Crystal growth index:  G   2 = T   ave2 × t   2   1/12   (b)
 
 
       is controlled so as to be 1500° C.·h 1/2  to 3500° C.·h 1/2 . 
     
     
       2. The cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 1 , wherein the crystallite size that is found from the diffraction peak on plane (003) is 80 nm to 200 nm. 
     
     
       3. The cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 1 , wherein the average particle size is 3μm to 20μm. 
     
     
       4. A manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery that comprises layered hexagonal crystal lithium nickel manganese composite oxide particles that are expressed by the general formula (A): Li 1+u Ni x Mn y Co z M t O 2  (where 0≦u≦0.20, x+y+z+t=1, 0.30≦x≦0.70, 0.10≦y≦0.55, 0≦z≦0.40, 0≦t≦0.10, and M is selected from one or more elements selected from among Al, Ti, V, Cr, Zr, Nb, Mo, and W); and further includes Na, Mg, Ca and SO 4 ; comprising:
 a crystallization process for obtaining nickel manganese composite hydroxide particles that include secondary particles that are formed from an aggregation of plural primary particles, and are expressed by the general formula (B):: Ni x Mn y Co z M t (OH) 2+α  (where x+y+z+t =1, 0.30≦x≦0.70, 0.10≦y≦0.55, 0≦z≦0.40, 0≦t≦0.10, 0≦α≦0.5, and M is at least one element that is selected from among Al, Ti, V, Cr, Zr, Nb, Mo, and W), and further includes Na, Mg, Ca and SO 4 , with the total amount of Na, Mg and Ca included being 0.01% by mass to 0.1% by mass, and the amount of SO 4  included being 0.1% by mass to 1.0% by mass; 
 a mixing process for obtaining a lithium mixture by mixing a lithium compound into the nickel manganese composite hydroxide particles that were obtained in the crystallization process so that the ratio of the number of atoms of Li with respect to the number of atoms of Ni, Mn, Co and M is 1:0.95 to 1.20; and 
 a calcination process for obtaining lithium nickel manganese composite oxide particles by performing calcination of the lithium mixture in an oxidizing atmosphere and at a calcination temperature of 850° C. to 1000° C., with T ave1  being the average temperature during the temperature rise from 650° C. to the calcination temperature, t ave2  being the amount of time for the temperature to rise from 650° C. to the calcination temperature, t ave2  being the average temperature while the temperature is maintained at the calcination temperature, and t 2  being the amount of time that the temperature is maintained at the calcination temperature, and wherein a crystal growth index (G 1 ) that is defined by an Equation (a)
   Crystal growth index:  G   1   =T   ave1   ×t   1   1/2   (a)
 
 
 
       is controlled so as to be 550° C.·h 1/2  to 1000° C.·h 1/2 , and a crystal growth index (G 2 ) that is defined by an Equation (b)
   Crystal growth index:  G   2   =T   ave2   ×t   2   1/2   (b)
 
 
       is controlled so as to be 1500° C.·h 1/2  to 3500° C.·h 1/2 . 
     
     
       5. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , wherein
 the crystallization process is a process for crystallizing the nickel manganese composite hydroxide particles by obtaining a reaction aqueous solution by mixing together a mixed aqueous solution in which Ni, Mn, Co and M are included so that the composition ratios are expressed by the general formula (B), an ammonium-ion donor and sodium hydroxide, and controlling the temperature of the reaction aqueous solution to be 35° C. or greater, and the pH value to be 10.5 to 12.0 at a standard liquid temperature of 25° C.; and 
 where of the metal elements of the mixed aqueous solution, at least nickel sulfate and manganese sulfate are used as the nickel source and manganese source. 
 
     
     
       6. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , wherein the mixed aqueous solution further includes 10 mg/L to 50 mg/L of Mg, and/or 10 mg/L to 30 mg/L of Ca. 
     
     
       7. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , wherein in the calcination process the amount of time for raising the temperature from 650° C. to the calcination temperature is 0.5 hours to 1.8 hours, and the amount of time that the temperature is maintained at the calcination temperature is 4 hours to 15 hours. 
     
     
       8. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , wherein in the calcination process, the amount of time from after the temperature reaches 650° C. to the end of calcination is 5 hours to 15 hours. 
     
     
       9. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , wherein the oxygen concentration in the oxidizing atmosphere is 18% by volume to 100% by volume. 
     
     
       10. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , further comprising a heat-treatment process before the mixing process for performing heat treatment of the nickel manganese composite hydroxide particles at 105° C. to 700° C. 
     
     
       11. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , wherein lithium carbonate, lithium hydroxide or a mixture of these is used as the lithium compound. 
     
     
       12. The manufacturing method for a cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 4 , further comprising a crushing process after the calcination process for crushing the lithium nickel manganese composite oxide particles that were obtained in the calcination process. 
     
     
       13. A non-aqueous electrolyte rechargeable battery comprising a cathode, an anode, a separator and a non-aqueous electrolyte, wherein the cathode active material for a non-aqueous electrolyte rechargeable battery according to  claim 1  is used as the cathode material of the cathode.